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The present investigation is to identify an optimum mix combination amongst 28 different types of artificial
lightweight aggregates by pelletization method with aggregate properties. Artificial aggregates with different combinations
were manufactured from fly ash, cement, hydrated lime, ground granulated blast furnace slag (GGBFS), silica fume,
met...
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Context 1
... results of loose bulk density (L.B.D) and rodded bulk density (R.B.D) of artificial aggregates with different binders were given in Table 6. It is noticed that the higher bulk density was observed for hydrated lime and GGBFS binder (FHG) as 919.4 kg/m 3 and lower bulk density for cement and calcium bentonite binder (FCCB) as 807.2 kg/m 3 . ...Similar publications
Demand to decrease the carbon footprint caused during the manufacturing of materials pushes the researchers studying in the construction industry to seek the production of earth friendly construction materials. The concept of alkaline activated geopolymer composite was developed in this context. This new phenomenon nowadays is considered it will ta...
The goal of this experimental study is to produce fly ash (FA)-based coarse aggregates by adding iron ore tailings (IOT) to the FA-based precursor as an additional mix component. The involvement of different types of binders-influential factors of both pelletization and geopolymerization that govern the production of FA-based coarse aggregates-was...
Today Vietnam is facing a seriously environmental challenge in handling fly ash and bottom ash from coal power plants with annual emissions of up to 15 million tons. Using the coal ashes to produce building materials is considered a main solution for this issue. Due to shortage of natural aggregates, using the ashes as aggregates in concretes achie...
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This study's main goal is to examine the durability and shrinkage properties of high-performance lightweight concrete (HPLC) which uses lightweight synthetic fly ash instead of some natural coarse aggregate. By combining 90% fly ash and 10% Portland cement by weight in a tilted rotating pan at room temperature and curing the aggregate for 28 days,...
Citations
... It is found out that the smaller the size of pellets, the higher the crushing strength [35]. The optimum disc pelletization angle is dependent on the critical revolution per minute, diameter of disc and angle of inclination [36], the optimum pelletization time and water content for maximum strength gain is 17 minutes and 28% by weight respectively [37]. As for the selection of binder material, study shows that sodium silicate binder is capable of lowering the eutectic point of raw material, allow it to be sintered at lower sintering temperature [22]. ...
... POFA and sodium silicate binder were mixed homogenously before pelletizing with a disc pelletizer of diameter 570 mm, operated at a fixed speed of 55 rpm and inclined at an angle of 74°. The design of pelletizing disc was based on literatures that studied the critical revolution per minute with respect to the disc diameter, speed and angle of inclination [36]. After POFA and sodium silicate mixture were successfully pelletized, fly figure 5 below, 2 load ring with maximum capacity of 2 kN and 50 kN respectively were used in monitoring of the loading force throughout the test. ...
This book series aims to become the leading annual book series in fields related to Civil, Structural, and Transportation Engineering. The goal is to gather scholars from all over the world to present advances in the relevant fields and to foster an environment conducive to exchanging ideas and information. The content of the book is as follows
... Therefore, it is worth noting that the binder content beyond a specific limit might inhibit the size and shape of pellets. A similar result was drawn by Gomathi et al. and Vali et al. [85,86] stated that the duration of pelletization influences the size, shape, and efficiency of aggregates. ...
In the construction sector, the material supply chain of aggregates is frequently disturbed due to seasonal unavailability, quarrying issues, and environmental norms. The production of artificial aggregates has gained prominence to conserve natural resources and promote green construction practices. The current study encompasses the production of alkali-activated artificial aggregates through cold-bonding pelletization technique using three different raw materials, including fly ash, ground granulated blast furnace slag, and seashell powder in binary and ternary blending combinations. The cold bonding was achieved by alkali activation of binders with the aid of a sodium-based alkaline solution, which acts as an activator and hydrating liquid. The fresh artificial aggregates were subjected to surface treatment using the same alkaline solution to enhance their characteristics. The mechanical properties of artificial aggregates confirmed their potential as a substitute for conventional aggregates by exhibiting crushing and impact values of 18.19–27.53% and 12.06–18.85%, respectively. The microstructural and mineralogical characteristics depicted dense microstructure and compact matrix. The study concludes that artificial aggregates can effectively replace natural coarse aggregate in making structural concrete with many economic, environmental, and technical advantages.
... A decrease in the compressive strength of concrete results from the replacement of natural aggregates with SLA particles because their strength is lower than that of the natural aggregate particles, according to earlier researchers on the impact of SLA produced by cold-bonding pelletization of pozzolanic materials [9][10][11]. Many attempts have been made in recent years to eliminate the weakness of artificial lightweight aggregate particles, such as changing the pozzolanic material fineness or using different types of pozzolanic materials with various chemical compositions altering the cement content [12,13].In the literature, many kinds of research have been published in which artificial pozzolans like slag, fly ash, silica fume, sodium and calcium bentonite, and other waste materials or by-products of heavy industrial operations were used in the manufacturing of LWA [13]. The cold bonding process is commonly employed to repurpose various waste materials and create lightweight aggregates for use in concrete. ...
... A decrease in the compressive strength of concrete results from the replacement of natural aggregates with SLA particles because their strength is lower than that of the natural aggregate particles, according to earlier researchers on the impact of SLA produced by cold-bonding pelletization of pozzolanic materials [9][10][11]. Many attempts have been made in recent years to eliminate the weakness of artificial lightweight aggregate particles, such as changing the pozzolanic material fineness or using different types of pozzolanic materials with various chemical compositions altering the cement content [12,13].In the literature, many kinds of research have been published in which artificial pozzolans like slag, fly ash, silica fume, sodium and calcium bentonite, and other waste materials or by-products of heavy industrial operations were used in the manufacturing of LWA [13]. The cold bonding process is commonly employed to repurpose various waste materials and create lightweight aggregates for use in concrete. ...
... In a study [13], the production of 28 different types of lightweight synthetic aggregate (LWA) was investigated using cement, fly ash, hydrated lime, metakaolin, slag, sodium, and calcium bentonite. The physical and mechanical properties of the aggregate mixtures were examined while the aggregate particles were hardened using the cold-bonded technique. ...
This study aimed to develop an eco-friendly, lightweight, and synthetic aggregate (SLA) based on clay suitable for use in structural lightweight concrete. The researchers utilized the cold-bonded pelletization process to agglomerate pozzolanic materials, specifically attapulgite extracted from a quarry, and crushed into a fine filler. The appropriate calcination temperature for manufacturing this clay as a pozzolanic material is 750°C. A total of 22 mixes were created using a combination of high reactive attapulgite (HRA) and cement (PC), with the attapulgite replacement rate varying from 100-50% by a 10% decrement. Different types of curing methods, including oven-dry, oven-water, room-water, and room-room, were applied. The aggregate properties were evaluated to determine density, specific gravity, water absorption, aggregate impact value, crushing strength, and compressive strength. The results revealed that it could produce lightweight synthetic aggregate from clay-based materials with a bulk density of 793kg/m3 with suitable physical and mechanical properties. As the percentage of cement in the mixture increased, the specific gravity and density were increased to 18.12% and 36.61%, whereas impact and crushing values of aggregate improved by 81.83%. This, in turn, leads to a significant boost in compressive strength up to 100.94%. Furthermore, there is a noticeable decrease in absorption. Moreover, the aggregate held under oven water positively impacts the strength development of cement-based composites.
... On the other hand, the result for aggregates samples with different Na 2 SiO 3 -to-NaOH ratios showed a more prominent and higher water absorption value than the solid-to-liquid ratio. The lowest water absorption value (30.42%) for the Na 2 SiO 3 -to-NaOH ratio was at ratio of 2.5, while the highest water absorption (47.37%) was determined to be at a ratio of 0.5 and the water absorption obtained was noted as exceeding the maximum water absorption of lightweight aggregate in which should not exceed 45% [14,32,33]. The decrement of water absorption was believed due to increment in silicon dioxide available for geopolymerization process with increasing Na 2 SiO 3 -to-NaOH ratios thus causing more development of geopolymer matrix. ...
... Lightweight aggregate concrete is produced as a nonstructural heat insulation material; hence, its thermal conductivity and properties are closely studied (Othuman and Wang 2011, Liu et al. 2014, Tasdemir et al. 2017, Tang 2017, Shoaei et al. 2017, Ali et al. 2018, Vali and Murugan 2020. Many studies also showed that lightweight aggregate concrete decreases weight and increases durability (Haque et al. 2004, Atmaca et al. 2017). ...
Lightweight aggregate concrete is a highly durable material that enables cost savings via weight reduction. This
material has been continuously improved by researchers and engineers, leading to a high demand for research on lightweight
aggregate concrete’s basic properties. This study conducts three-point bending tests and analyzes the tensile properties of
lightweight aggregate concrete load–crack mouth opening displacement and load–deflection curves. A trilinear tensile softening
curve was used to identify the tensile properties of material. The necessary parameters are derived by conducting inverse
analysis through the ant colony optimization (ACO) method. The intraclass correlation coefficient of less than 0.01 sufficiently
confirmed the reliability of inverse analysis, allowing us to obtain the fracture energy. It was proposed both physical properties
of lightweight aggregate concrete and a fracture energy prediction equation that uses the ligament depth and width of the
specimen as parameters. In this prediction equation, the experimental results are well predicted with a standard deviation of
0.107 and a coefficient of variation of 0.105 by determining the experimental constants using the existing 85 experimental data
of lightweight aggregate concrete.
... For instance, Kamal and Mishra (2020) [60] reported on the specific gravity of the fly ash aggregates as well as raw materials, including fly ash and binder, and the amount of void space in the aggregate. In addition, whenever cold-bonded aggregate was combined with other pozzolanic binding materials, such as GGBS, the specific gravity was found to be as high as 2.42, in which the hydrated lime acts as a primary binder [61]. Previous research on the determination of specific gravity of aggregates can be summarized as in Table 2. From Table 2, the specific gravity of lightweight aggregate was found to be in the range from 1.41 to 2.2. ...
As the demand for nonrenewable natural resources, such as aggregate, is increasing worldwide, new production of artificial aggregate should be developed. Artificial lightweight aggregate can bring advantages to the construction field due to its lower density, thus reducing the dead load applied to the structural elements. In addition, application of artificial lightweight aggregate in lightweight concrete will produce lower thermal conductivity. However, the production of artificial lightweight aggregate is still limited. Production of artificial lightweight aggregate incorporating waste materials or pozzolanic materials is advantageous and beneficial in terms of being environmentally friendly, as well as lowering carbon dioxide emissions. Moreover, additives, such as geopolymer, have been introduced as one of the alternative construction materials that have been proven to have excellent properties. Thus, this paper will review the production of artificial lightweight aggregate through various methods, including sintering, cold bonding, and autoclaving. The significant properties of artificial lightweight aggregate, including physical and mechanical properties, such as water absorption, crushing strength, and impact value, are reviewed. The properties of concrete, including thermal properties, that utilized artificial lightweight aggregate were also briefly reviewed to highlight the advantages of artificial lightweight aggregate.
... The CBAs are less energy-intensive and more cost-effective than the aggregates prepared by sintering methods [41], and cold-bond granulation of solid waste receives extensive attention as a stabilization technology for the reuse of waste in the manufacture of construction materials [42]. Technically, the cold-bond method involves a binding phase to glue other components [43,44], which yields vast choices of the source of raw materials. Such flexibility in aggregate composition has enabled different kinds of industrial wastes [45][46][47][48][49][50][51] to be successfully used as the raw materials for aggregate preparation. ...
While traditional disposal of phosphogypsum either occupies excessive amounts of land or causes serious pollution, novel recycling of phosphogypsum is desirable. Making phosphogypsum-based cold-bonded aggregates (PCBAs) through granulation technology is a potential recycling strategy. In this study, the quality of the recycled PCBAs is assessed, considering physical properties, mechanical strength, impurity stabilization ability, and microstructure. With the increase of phosphogypsum content from 60% to 90%, 28-day bulk density of the PCBAs decreased from 1080 to 950 kg/m³, cylinder compressive strength in over dry (OD) condition decreased from 16.5 MPa to 3.9 MPa, and water absorption increased from 5.9% to 13.6%. SEM, XRD, and MIP analyses showed that as the phosphogypsum content increased, hydration products in the aggregates diminished and proportion of harmful pores (greater than200 nm) increased. Leaching test on 28-day PCBAs showed a reduced concentration of phosphorus and heavy metals in the leachate compared to the leaching of the original phosphogypsum. The study concluded that the PCBAs with the phosphogypsum content up to 80 % are qualified lightweight aggregates (LWAs) for concrete.
... Over the recent years, practical development has been produced in the growth of advanced lightweight construction materials from various industrial by-products in the form of artificial lightweight aggregates (ALWA). The physical and mechanical properties of different artificial aggregates manufactured from industrial by-products were studied earlier [1][2][3][4][5][6][7]. The compatibility of ALWA manufactured through pelletization followed by the hardening process with fly ash is tough to predict due to various physicochemical aspects. ...
... Earlier studies noticed that the physical and mechanical properties of ALWA depend on the type and percentage of binder [4][5][6][15][16]. The microstructure and properties of ALWA were altered by applying heat and polymers to attain their changes in their properties (strength, water absorption) and pozzolanic action [17]. ...
... When the disc pelletizer was positioned lesser than 45 0 angle and operated at higher speeds did not have sufficient strength because of big pores [10,13,[26][27]. To attain the highest aggregate production efficiency, the pelletizer was fixed at a 36 0 angle and speed at 55 rpm with 27% water content [2,[4][5]28]. The artificial lightweight aggregates as shown in Fig. 2 were manufactured with 80% fly ash, 10% cement, and 10% hydrated lime binder combination with 0%, 0.10%, 0.12%, Table 3. ...
The present investigation experimentally tested the impact of alkali-resistant glass fibres (AR-GF) on manufactured aggregate properties through cold-bonding pelletization and the impact of manufactured aggregates in the production of lightweight concrete. The aggregates manufactured in this study were produced with a combination of 80% fly ash, 10% cement and 10% hydrated lime at 0%, 0.10%, 0.12%, 0.14%, 0.16%, 0.18%, 0.20% addition of AR-GF. Seven mixture combinations of aggregates were tested with various properties like production efficiency, bulk density, specific gravity, water absorption, and impact strength. Selected the optimum mixture combination of manufactured aggregate to study lightweight concrete’s slump, density, and compressive strength and compared with natural aggregate concrete. Test results on manufactured aggregates indicate that, as the percentage addition exceeds 0.18% of AR-GF, aggregate properties do not show adequate results. Also, the lightweight concrete result shows that slump value increases with manufactured aggregate. Similarly, the compressive strength result satisfies
the structural grade for concrete. The utilization of manufactured aggregates in the production of light-weight concrete results in both economic and ecological benefits.
... In spite of the calcination process necessary in metakaolin production, Sullivan et al. [20], who reviewed the study by Selmani et al. [21], stated that the manufacture of metakaolin involved much lower calcining temperatures and emitted less carbon dioxide than Portland cement. Therefore, metakaolin is gaining popularity in various construction applications, as mentioned in other studies [22,23]. As one example of its applications, Attanasio et al. [24] used metakaolin, fly ash and furnace slag to produce alkali-activated mortars, in order to study the effect of binder compositions by focusing on workability and compressive strength. ...
This study proposes the use of a non-destructive testing technique, based on piezoelectric bender element tests, to determine the initial and final setting times of metakaolin geopolymer pastes. (1) Background: Metakaolin geopolymer is a new eco-friendly building material that develops strength rapidly and is high in compressive strength. (2) Methods: The initial and the final setting times were investigated via bender element and Vicat needle tests. Metakaolin powder was prepared by treating kaolin at 0, 200, 800, 1000, and 1200 °C. All metakaolin powder samples were then mixed with geopolymer solution at different mixing ratios of 0.8:1.0, 1.0:1.0, 1.2:1.0, and 1.5:1.0. The geopolymer solution was prepared by adding 10 normal concentrations of sodium hydroxide (10 N NaOH) to sodium silicate (Na2SiO3) at various solution ratios of 1.0:1.0, 1.0:1.2, 1.0:1.5, 1.0:2.0, 1.2:1.0, 1.5:1.0 and 2.0:1.0. (3) Results: The optimum temperature for treating metakaolin is established at 1000 °C, with a mixing ratio between the metakaolin powder and the geopolymer solution of 1.0:1.0, as well as a solution ratio between NaOH and Na2SiO3 of 2.0:1.0. (4) Conclusions: The use of piezoelectric bender elements to determine the initial and final setting times of metakaolin geopolymer pastes is a useful method by which to detect geopolymerization by shear wave velocity in a real-time manner. Moreover, the penetration of the Vicat apparatus can confirm the setting times at specific intervals. The relationships between the shear wave velocity and the Vicat penetration appear to be linear, with an initial setting time of 168 m/s and a final setting time of 187 m/s. Finally, the optimum metakaolin geopolymer pastes are applied to improve laterite soils, as measured by CBR tests.
... In modern days, there has been a developing interest in the utilization of industrial by-products to manufacture artificial light-weight aggregates [7,[11][12][13][14][15][16][17]. Artificial aggregates could be manufactured using the conversion of different binder materials and manufacturing methods like pelletization followed by a hardening process with cold-bonding, sintering, and autoclaving [1,5,8,12,[18][19][20][21][22][23]. Cold-bonding is a kind of technique that represents the capacity of pozzolanic binder materials reaction at the time of cold-bonding (water curing). ...
... Cold-bonding is a kind of technique that represents the capacity of pozzolanic binder materials reaction at the time of cold-bonding (water curing). Artificial aggregates were left to cure in water for several days at room temperature binder materials in aggregates react with calcium hydroxide to produce solid bonding material with desired strength of aggregates to be utilized in concrete production [21][22][23]. On the other side, the sintering process mostly depends on atomic energy supply, which is a usual application for large-scale manufacturing of artificial lightweight aggregates. ...
... Since, directly after pelletization of artificial aggregates were treated with elevated temperatures up to 1200°C, and turned into ready for utilization without preservations for a long time curing. The properties of LWAs depend on the parameters like type of binder material, pelletization time, water content, and hardening process [21][22][23]. In some, the nations like the United States of America, the United Kingdom, Russia, Germany, and Poland are manufacturing artificial aggregates with various trade names in the market [19]. ...
This study examines the performance of lightweight concrete incorporating manufactured lightweight aggregates with industrial by-products. The physical and mechanical properties of cold-bonded aggregates manufactured through pelletization technique with 80% fly ash, 10% cement, and 10% metakaolin with the addition of 0.2% alkali-resistant glass fibers. The manufactured aggregates have been tested with different properties like production efficiency, bulk density, specific gravity, water absorption, and impact strength thereby compared with natural aggregate results. Further, the study on properties of lightweight concrete produced with the replacement of ordinary portland cement (OPC) by ground granulated blast furnace slag (GGBFS) at different percentages varies from 0% to 50%. The lightweight concrete performance was assessed based on the slump cone test, density, compressive strength, split tensile strength, and water absorption at different curing ages. It was noticed from the results that the optimum performance of lightweight concrete was attained at 40% replacement with GGBFS. It is observed from the results that the replacement of natural aggregate by manufactured aggregates and cement by GGBFS achieved desired strength to be used as a structural material. Usage of industrial by-products in aggregates and concrete production results in both economic and environmental benefits.
